A typical dynamic loudspeaker usually includes a motive power system, a loudspeaker cone, and a suspension system, in which the motive power system includes a permanent magnet A, an upper iron plate B, gap C, and a voice coil D. The loudspeaker cone E, which is a diaphragm for moving air, is usually formed as a conically shaped or semi-spherically-shaped acoustic bowl. The suspension system composed of a damper and an annular suspension member is provided for drawing the loudspeake cone to move in a specified direction.
The loudspeaker works in such a way that a magnetic force perpendicular to the directions of a current and a magnetic field of the permanent magnet is generated by flowing the current through the voice coil suspended inside the permanent magnet of the loudspeaker, and the generated magnetic force will cause the movable coil to oscillate up and down within a gap (a space between the voice coil and the permane magnet), and thereby the loudspeaker cone attached to the voice coil is able to vibrate up and down and reproduce sound at the frequency of the applied electrical signal. Therefore, the electrical energy can be converted into the sound energy in a loudspeaker.
Generally, the conventional loudspeaker cone is made of paper, cloth, metal material or the like. The material used depends on the desired acoustic quality, strength, and the like. For example, the paper cone is cheap, but it is not strong enough, and is easily broken up due to high frequency vibration, and the acoustic quality will be poor if a hole is formed in the louspeaker cone.
The metal cone is strong enough, but it is heavyweight and expensive.
The cloth cone is cheaper than the metal cone, but it is not strong enough, has poor pressure-resistance, and is easily deformed after long-term use.